Short term

After a person has consumed a certain amount of alcohol, they will experience its intoxicating effects. Some effects include blurred vision, slurred speach, impaired balance, loss of muscle coordination, reduced inhibition, behaviours the person may not usualy take part in, and if there is too much of the substance consumed, the person may experience vomitting as a way to excrete the excess alcohol. If there is enough alcohol to due so, the person may slip into a coma or even die. Excessive drinking causes the body to use up more water than usual, leading to dehydration causing the blood to thicken making it easier to clot. This also helps leads to what is known as a "hangover", a mild for of withdrawal mixed with the effects of dehydration, often accompanied by vomitting and a severe headache.

Long term

The organ which breaks down the alcohol is the liver. Long term excessive consumtion can exhaust the liver and lead to disease, cirrhosis and cancer of the liver. Heart complications such as high blood pressure(leading to a strokes) can occur, and serious situations can lead to cardiomyopathy which is permanent damage to the heart muscle. By far the most serious long term effect of alcohol is the possibility of addiction. As you would assume, the more frequent you consume large amounts, the higher the likelyhood of developing an addiction is.
cirrhosis-liver.jpg
Notice the difference between a healthy liver and a Cirrhosis liver


http://www.alcoholism-solutions.com/long-term-effects-of-alcohol.html